Noted for its line of easy-to-wear and excellent headphones, AKG has introduced an “improved” line of professional headphones, including updates of the venerable K240 (now K240 Studio) and the K270, the new K271 Studio reviewed here.
Product PointsApplications: Studio, broadcast, live sound
Key Features: Closed-back; Varimotion drivers; self-adjusting headband; user-replaceable cable
Contact: AKG at 615-620-3800, Web Site.
The K271 Studio ($249 retail), and other AKG models, feature new Varimotion XXL driver technology, auto-mute switch and a removable, high-quality cable that makes for easy replacement if broken.
The new Varimotion XXL driver diaphragm is thinner and more elastic toward the outside edge, which is said to offer deeper bass and more accurate midrange and treble. Frequency response is now rated from 16 Hz to 28 kHz (with no tolerance listed, as is the case with most headphone specs).
AKG headphones are not known for their easy drivability, but the new line has improved sensitivity over previous models. With its 55 ohm impedance and new drivers, the K271 output is factory rated at 91 dB SPL at 1 milliwatt, measured close to the center of the headphone.
The headband is self-adjusting, and the gimbal-mount cup suspension, combined with the ear cushions, make this headphone one of the most comfortable I have ever worn. The 10-foot cable removes for easy transportation, replacement, or if you want to keep on your headphones, but walk away from the gear. The audiophile-quality, oxygen-free cable is terminated with an 1/8-inch mini plug, but comes with a screw-on, 1/4-inch stereo adapter.
The auto-mute function is activated by two switches (one on each side) when the headphone is removed form the user’s head. The reduced tension of the headband engages the switches, muting the audio. This feature was designed for broadcasters, who often remove the headset when the mic is on, creating the potential for ear-splitting feedback.
The headphones weigh in at a light 8.5 ounces. AKG does not supply a carrying pouch or a case for storage.
I tried the K271s with a number of sources including an Alesis MasterLink recorder, Sony DAT deck, Fostex CR-200 CD recorder, Panasonic RP-91 DVD-Audio player, Benchmark DAC-1 24-bit/96 kHz digital converter with built-in headphone amp, and the headphone output of a Midas Venice 160 console.
My first impression was, Wow! This headphone is comfortable. My second impression was how well it isolates. It easily reduced the level of barking dogs and other noises that often occur in my studio. Live sound guys should covet the 271 as well. Short of active noise-canceling, headphones, these AKG cans are some of the best isolating ‘phones you can get.
Though useful for broadcast, the auto-mute made it impossible for me to plug-in the headphones into a source, throw them in a corner and break them in for a couple of days. I had to prop open the headband to get enough tension so the mute switches would not activate. A bicycle helmet finally did the trick.
Sound-wise, the AKGs sounded a lot more “present” than either my reference, closed-back Sony 7509 or Grado 325, a semi-open back headphone. The AKG literature claims a “bigger” sound than other headphones, and it is – especially the high midrange and in the 5 kHz – 8 kHz treble.
With an AudioControl RTA-3050 and a noise generator, I did some informal close mic measurements and found quite a presence peak at 8 kHz. The Sony 7509 had a narrower peak at 12 kHz, but it sounded down right dark compared to the AKGs.
But this upward presence was not objectionable or harsh. I found myself getting used to it quickly, and it helped me find little noise anomalies in the background of a several recordings. Overall, the bass was tight and deep, and the stereo imaging was excellent.
As previously mentioned, the AKGs are not known for their easy drivability. Most of my devices drove them to the desired level with a bit more twisting of the knobs. However, two portable CD players just could not get the cans loud enough – even when wide open.
If you want a premium, closed headphone that isolates among the best and is very comfortable to wear, the AKG K271 should be on your want list. The sound is a bit more present than other headphones, but the sonics are clean and revealing with excellent imaging.